We routinely work on drives that are on the verge of failure. The technician is careful to only request data that is necessary and also to only expect the read of a block of data to work once more. The PC-3000 data extractor is filesystem aware allowing us to target important files. All successfully read data blocks are saved in case the filesystem needs the same data again. Recovery of currupted files tends to wear out the drive heads. This is called “digging” for the data and is usually attempted after the easier files.